Canadian miner Centerra Gold has provided a new life-of-mine (LoM) plan for the Mt Milligan mine, in British Columbia, including an extension of the mine life by four years to 2033.
The deposit contains combined proven and probable mineral reserves of 246.2-million tonnes at 0.37 g/t gold and 0.18% copper, containing 2.9-million ounces of gold and one-billion pounds of copper.
The reserves have been classified about 30% proven and 70% probable on a tonnage basis.
Compared with the 2020 technical report, LoM total payable gold ounces would increase by more than 0.8-million ounces and payable copper produced by 191-million pounds from 2022 onwards.
Over the remining 11-year mine life, Mt Milligan will produce 1.93-million ounces of gold and 751-million pounds of copper. On average, the mine will produce 175 000 oz/y of gold and 68-million pounds a year of copper at an all-in sustaining cost of $756/oz.
Centerra says it will provide a production and cost guidance for 2023 to 2025 in early 2023, which will take into consideration the recent inflationary cost pressures.
Mt Milligan’s after-tax net present value is estimated at $486-million at a 5% discount rate using a gold price of $1 500/oz and copper price of $3.25/lb and an estimated $797-million at gold and copper prices of $1 700/oz and $3.50/lb, respectively.
Centerra notes that significant exploration potential exists at the Mt Milligan mine peripheral to the current openpit and within the wider tenement holdings. Outside of the immediate deposit, greenfield exploration to identify new porphyry copper/gold deposits and low sulphidation epithermal gold/silver deposits within the Mt Milligan tenement package continues.